CVE-2026-53613 util-linux mount target TOCTOU allows local privilege escalation
Local attackers can exploit a race condition in util-linux mount to escalate privileges to root by redirecting authorized mounts to sensitive system paths.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53613?
CVE-2026-53613 is a high-severity vulnerability in util-linux, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges. Versions 2.41.5 and 2.42.2 pin targets for the new mount API, and 2.42.4 pins legacy targets through `/proc/self/fd`; the documented legacy fallback without `/proc` remains affected.
Weakness: CWE-367
Which versions are affected by CVE-2026-53613?
How do I fix CVE-2026-53613?
Upgrade to a fixed version.
Is CVE-2026-53613 being exploited?
There is no known exploitation of CVE-2026-53613 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as ALPINE-CVE-2026-53613, AZL-108555, BELL-CVE-2026-53613, DEBIAN-CVE-2026-53613, ECHO-c24c-41a0-9a74, GHSA-8gj5-72r3-428g and 2 more.